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(No Model.) 2 Sheets-Sheet 1.

' J. W. KEN'NA.

TILTING GHAIR IRON.

.Patented Dec;.`20,`1887r HHMN'H.

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l J. W. KENNA.

TILTING CHAIR IRON.

No. 374,970. Patented Dep. 20,1387.'

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UNITED STATES PATENT OFFICE.

JOSEPH YV. KENNA, OF CHICAGO, ILLINOIS, ASSIGNOR TO JAMES lV. VAIL, TRUSTEE, OF PORT WASHINGTON, WISCONSIN.

TILTING-CHAIR IRON.

SPECIFICATION forming part of Letters Patent No. 374,970, dated December 20, 1887.

Applicatinn filedSeptenlbcr 22, 1884. Serial No. 143,638. (No model.)

To all whom, it may concern:

Beit known that I, JOSEPH W`. KENNA, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and usel'ul Improvements inv Irons for Tilting-Chairs, of which I do declare the following to be a full, clear, and exact description, reference being hadV to the accompanying drawings, forming I0 part of this speeitcation.

My invention relates to that class of tiltingchair irons in which the spider'frame to support the ohairseat is pivotally joined to the vertical standard located at the upper end of the screw-spindle. An adjustable coil-spring located between the spider-frame and the standard serves to regulate the tilting moveI ment about the pivotal connection.

The invention consists in certain novel eom- 2o binations and arrangements of parts,hereinaf ter fully described,and particularly defined by the claims at the end of this specification.

Figure 1 is a view in side elevation, partly in vertical section, of the improved chairirons, the seat and a portion of the base of the chair being shown attached thereto. Fig. 2 is a view of said irons, partly in vertical section and partly in side elevation. Fig. 3 is a rear view of the irons,parts being omitted for pur- 3o pose of better illustration. Fig. 4. is a front view ofthe chair-irons, parts being omitted. Figs. 5, 6, and 7 are detail views ofthe washer at the front of the coiled spring. Figs. S, 9, `10, and 11 are detail views ofthe washer at the rear of the coiled spring. Figs. 12, 13, and 14 are detail views of the pivotal plate against which the head of the adjusting rod bears. Fig. 15 is a view in side elevation ofa slightly modified form of my invention. Fig. 16 is a 4o View in vertical longitudinal section ot' such modification. Fig. 17 isa front view, and Fig. 18 a rear view, of such modification.

A designates the base of the chair, to which is secured,in usual manner,the nut A', adapted to receive the spindle B. To the top of this spindle is connected what I designate the standard C, having the yoke-shaped arms c rising therefrom. These arms c are provided on their rear sides wit-h the grooved lugs or 5o seats c', and at their expanded tops are formed with the shoulders o2 c3, and with suitable perforations to receive the pivotpin G. A spider, D, having arms d, for attachment to the seat ot' the chair, is provided with the perfo rated lugs d', adapted to receive the pivot-pin 55 C', with stops d2 and d3, adapted to bear upon the shoulders o2 o3 of the yokearms, and with the depending bearingplate D', having the long slot d" therein. This depending plate is formed ofsuch shape and size, as shown, that when the several parts are in position for use it will be free to move between` the yokearms of the standard.

Against the yokearnis c bears the pivotal plate E, having the arms e, with inwardly-projecting ends arranged to fit within the seats c', and having the central squared perforation,

e', adapted to receive the square end of the headed adjusting-rod F. This rod F passes through the slot el* of the bearing-plate D,and 7o upon it is held the coiled spring G, by means ot' the threaded handwheel H, which serves to regulate the tension of the spring. The inner end of this coiled spring lits over the hub of the washer I, which rests against the bear- 7 5 ingplate D, and through the slotfi of this washer passes the adj listing-rod F.

Upon the rear side ofthe washer I are formed the pins ft2, adapted to fit corresponding depressions (seen in Fig. 4) in the bearing-plate 8e D', and the shoulder t3 of this washer is out upon an incline to form a more even bearing for the end of the spring. Between the outer end of the coiled spring and the hand-wheel H is held the washer K, (seen in" detail in S5 Figs. 5, 6, and 7,) having the hub k, over which the spring tits, and having the inclined shoulder 7c', to form a seat for the end of the spring.

When the several parts are in position for use, they will be relatively arranged as shown 9o in Figs. 1 to 4 of the drawings. The force of the coiled spring will retain the chair-seat normally in horizontal position; but when sufficient pressure is exerted to tilt the chair the depending bearing-plate D will swing slightly forward between the yoke-arms c, thus tending to compress the spring, the tension of which can be controlled at will by the adjustment of the hand-wheel H.

It is to be noted as an important feature. of 10o my present invention, and one which I desire to claim broadly, that the pivotal plate E serves to sustain the adjusting-rod in such manner that this rod can shift with the tilting movement of the chair, and hence all strain upon the rod,and consequent danger of breakage, is avoided.

It will also be observed that by forming the rod with a squared end iitting within a correspondinglysquared opening-of the pivotal plate this plate prevents the turning of the rod when the hand-wheel is turned to regulate the tension of the coiled spring.

In the modified construction illustrated in Figs. 15 to 18 it will be seen that the coiled spring bears against the bearing-nutV, which bears against the face of the depending plate D', which in this instance is upon the front side of the standard. The standard below its pivot-arms is furnished with a perforation to receive the adjusting-rod F, and upon itsback with a suitable seat for the pivotal plate E. The end of the slot in the depending plate striking the adjusting-rod limits the forward movement of the chair seat, and suitable stops or shoulders, w, on the spider and standard restrict its backward movement.

By the construction and arrangement of parts in the manner above stated a simple, cheap, durable, and effective tilting mechanism for chairs is secured.

Y I am well aware that in Volffs Letters Patent No. 197,195, November 13, 1877, for tilting-chairs, there is shown a pivot-plate at the terminus of and in piece with the adjustingrod; but said plate seats against the radiallymoving dependent lugs or extensions of the tilting spider-frame, and not against the tiXed standard, as in my construction. The coilspringis permanently set upon the standard, and, together with the rod, has a strictly rectilineal play during the tilting movement, whereas in my device the spring and rod are constantly subjected to a radial shift or strain, which it is the function of the pivot-plate to compensate and rcadjust. Obviously the organization of the parts and the mode of operation are markedly different in the Tolft patent from that which I employ.

In my former Letters Patent, No. 294,391, arch 4, 1884, the construction of the parts more nearly resembles the present invention; but the adjustingrod is fixed rigidly to the standard,

and not pivotally set thereon, as by my im-A provement. Both rod and coil-spring are Aconsequently subjected to strain and disarrangennent during the tilting play, to remedy which is one purpose of my invention.

The general combination, with a spiderframe and a vertical standard about which said frame tilts, of an adjustable coil-spring pivotally set and mounted substantially at its end faces between thev spider and standard, respectively, to control the tilting movement, is no part of the present invention; nor does the same involve the presence in such combination of a bearing-nut mounted upon the adjusting-rod and having a spiral-like face to seat one end of the pivotal and adjustable coil-spring. These features of organization are made the subject of claims in a separate application, which has been iiled byme prior hereto, dated September 15, 1884, Serial No. 143,149.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In tilting-chair irons, the combination, with the spindle and the standard having the pivot-arms, ofthe spider pivoted to said arms, and having a downwardly-projecting bearingplate for the spring, an adjusting-rod, a pivotal plate-to sustain said rod and set against the standard, a coiled spring, and an adjusting hand-wheel, substantially as described.

2. In tilting-chair irons, the combination of-the spindle, the standard having yokeshaped arms, the spider pivoted to said standard, and having the slotted depending bearing-plate, of ay size permitting it to move between the yoke-arms ot` the standard, the adjusting-rod, the pivotal plate having arms, substantially as described, bearing against the yoke-arms of the standard, the coiled spring extending beneath the front portion of the chair-seat, and the adjusting hand-wheel, substantially as described.

3. In tilting-chair irons, thc combination, with the standard, a spider pivoted thereto, a coiled spring, and an adj ustingrod and handwheel, of a pivotal plate bearing against the standard and sustaining the adjusting-rod, substantially as set forth, whereby said rod accommodates itself to the radial shift of the spider, substantially as described.

4t. In tiltingchair irons, the combination, with the standard, a spider pivotally secured thereto, a coiled spring, and an adjusting-rod having a square portion and hand-wheel, of a f pivotal plate having a squared opening through which the squared end of said rod passes, and which serves to prevent the turning ot' the rod with the adj listing-wheel, substantially as described.

5. In tilting-chair irons, the combination, with the standard, of the spider-frame pivoted thereto and having the depending bearing-plate, a coil-spring, an adjusting-rod sustained by said standard, ahand-wheel, anda bearing-nut to receive the end of the coilspring, said nut resting against the face of the plate depending from the spider-frame, substantially as described.

In testimony whereof I have hereunto set my hand this 18th day of September, 1884i.

JOSEPH V. KENNA.

Witnesses:

GEO. P. FIsHER, J r., JAMES H. Prinzen.

IOS

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